Instructions:
- Par-Boil the Potatoes: Place cut potatoes in a large saucepan, cover with cold water, add a pinch of salt, and bring to a boil. Cook until just tender but still holding their shape (about 8–10 minutes). Drain thoroughly.
- Dry the Spuds: Return the drained potatoes to the empty hot saucepan over low heat for 1 minute, shaking gently to dry out the surface. Set aside.
- Bloom the Whole Spices: Heat a large frying pan over medium heat. Add mustard seeds and cumin seeds. Cook until the mustard seeds begin to pop (about 30 seconds).
- Sauté Aromatics: Add the chopped onion to the pan. Sauté gently until softened and translucent (about 5 minutes). Add the minced garlic, grated ginger, and green chilli (if using). Cook for 1 minute until fragrant.
- Toast Ground Spices: Reduce the heat slightly. Stir in the turmeric, ground coriander, garam masala, and chilli powder. Cook for 30 seconds, stirring constantly until fragrant. Stir in the tomato puree.
- Deglaze and Simmer: Pour in the vegetable stock (or water). Bring to a gentle simmer, scraping up any browned bits from the bottom of the pan.
- Combine and Finish: Gently fold the par-boiled potatoes into the spice mixture, being careful not to mash them. Cover the pan and let it simmer gently for 5–8 minutes, allowing the potatoes to absorb the flavour.
- Final Seasoning: Remove the lid. Check seasoning. Stir through the fresh lemon juice and chopped coriander. Serve hot.